The Il-76 has seen extensive service as a commercial freighter for ramp-delivered cargo, especially for outsized or heavy items unable to be otherwise carried. It has also been used as an emergency response transport for civilian evacuations as well as for humanitarian aid and disaster relief around the world. Because of its ability to operate from unpaved runways, it has been useful in undeveloped areas. Specialized models have also been produced for aerial firefighting and zero-G training.

The aircraft was first conceived by Ilyushin in 1967 to meet a requirement for a freighter able to carry a payload of 40 tons (88,000 lb) over a range of 5,000 km (2,700 nmi; 3,100 mi) in less than six hours, able to operate from short and unprepared airstrips, and capable of coping with the worst weather conditions likely to be experienced in Siberia and the Soviet Union's Arctic regions. It was intended to replace the Antonov An-12. Another intended version was a double-decked 250-passenger airliner but that project was cancelled. The Il-76 first flew in March 1971 (1971-03).[4]

Production of Il-76s was allocated to the Tashkent Aviation Production Association in Tashkent, Uzbekistan, then a republic of the Soviet Union. Some 860 of the basic transport variants were manufactured.[5] In the 1990s, modernized variants also equipped with Soloviev D-30 turbofan engines,[6] were developed (MF, TF), with a cargo compartment 20 m long by 3.4 m wide by 3.4 m tall; these larger variants were not produced in significant quantity due to the financial difficulties being experienced by the Russian Air Force, which was the primary operator of the type.[citation needed] The prototype of the Il-76MF, conducted its first flight on 1 August 1995.[citation needed]

From 2004 onwards, a number of aircraft in commercial service were modernized to the Il-76TD-90VD version; this involved the adoption of the newly developed PS-90 engine to comply with European noise limitations.[1] In 2005, the People's Republic of China placed an order for 34 new Il-76MDs and four Il-78 tankers.[citation needed] In June 2013, Russian military export agency Rosoboronexport announced an order by China for 12 Il-76MD aircraft.[7]

It was announced in 2010 that the production of a modernized Il-76, the Il-76MD-90A (also known as project Il-476 during the design stage), would begin; a proposed new production line would be located in Aviastar's facility in Ulyanovsk, Russia, and be operated in cooperation with the Tashkent works.[5] At that point, the construction of two Il-76MD-90A prototypes had begun at the Ulyanovsk facility.[10] The 1st serial production Il-76MD-90A was rolled out at Aviastar's Ulyanovsk plant on 16 June 2014.[11] On 29 April 2015, it was reported that the Russian Air Force received the first Il-76MD-90A built at the Ulyanovsk plant "Aviastar-SP" from the 2012 contract for 39 aircraft.[12][13]

First aircraft were delivered to the Soviet Air Force in June 1974.[1] Next it became the main Soviet strategic transport aircraft. From 1976 it was operated by Aeroflot.

Between 1979 and 1991, the Soviet Air Force Il-76s made 14,700 flights into Afghanistan, transporting 786,200 servicemen, and 315,800 tons of freight. The Il-76 carried 89% of Soviet troops and 74% of the freight that was airlifted. As Afghan rebels were unable to shoot down high-flying Il-76s, their tactics were to try and damage it on takeoff or landing. Il-76s were often hit by shoulder-launched Stinger and Strela heat-seeking missiles and large-calibre machine gun fire, but because the strong airframes were able to take substantial damage and still remain operational, the aircraft had a remarkably low attrition rate during this period of conflict. Building on that experience, the bulk of the Canadian Forces equipment into Afghanistan was flown in using civilian Il-76s.[14] In 2006, the Russian Air Force had about 200 Il-76s. Civilian users in Russia have 108.[5]

On August 3, 1995, a Il-76 piloted by a Russian crew was forced down by a Taliban fighter plane sparking the Airstan incident.

In 2004, a Chinese People's Liberation Army Air Force (PLAAF) Il-76 carried out a flight mission in Afghanistan, and later in 2011, PLAAF Il-76s were sent to Libya to evacuate Chinese citizens. The two missions were the reported first steps of PLAAF developing long-range transportation capacity.[15]

On 23 March 2007, a Transaviaexport Il-76 was shot down by an anti-aircraft missile while taking off from Mogadishu, Somalia. Everybody on board, seven crew and four passengers, was killed.[16]

Syrian Air Force Il-76s, operating as civil Syrianair aircraft, have been reportedly used to ship weapons, money and other cargo from Russia and Iran to Syria, according to a defected Syrian military pilot. Since the start of the war, in April 2011 (and up to July 2012), around 20 military flights have been conducted to and from Tehran, via Iraqi airspace. Further information exposes that since around 2012, Syrian Il-76s have regularly flown to Moscow's Vnukovo Airport to fetch shipments of Syrian banknotes that have been useful to Bashar al-Assad's government to survive Western sanctions.[17][18][19]

Built without military equipment but designated as Ms and MDs (Gordon – 'Falsies')

Il-76MD-90

An Il-76MD with quieter and more economical Aviadvigatel PS-90 high-bypass turbofan engines.

Il-76MF

Stretched military version with a 6.6 m longer fuselage, PS-90 engines, maximum takeoff weight of 210 tonnes and a lift capability of 60 tonnes. First flew in 1995, not built in series so far,[1] just built for Jordan.

Il-76PP

ECM aircraft, major problems with ECM equipment on the Izdeliye-176 only.

Complete removal of Military equipment, identified by crude cover over OBIGGS inlet in Starboard Sponson.

Il-76P / Il-76TP / Il-76TDP / Il-76MDP

Firefighting aircraft. The Il-76 waterbomber is a VAP-2 1.5 hour install/removal tanking kit conversion. The Il-76 can carry up to 13,000 U.S. gallons (49,000 liters) of water; 3.5 times the capacity of the C-130 Hercules. Since this kit can be installed on any Il-76, the designation Il-76TP, Il-76TDP are also used when those versions of the Il-76 are converted into waterbombers. The Il-76P was first unveiled in 1990.

Domestic Chinese airborne early warning and control conversion of Il-76, developed after A-50I was cancelled and currently in service with the armed forces of China.

CFTE engine testbed

The China Flight Test Establishment (CFTE) currently operates a flying testbed converted from a Russian-made Il-76MD jet transport aircraft to serve as a flying testbed for future engine development programmes. The first engine to be tested on the aircraft is the WS-10A "Taihang" turbofan, currently being developed as the powerplant for China's indigenous J-10 and J-11 fighter aircraft. Il-76MD #76456, acquired by the AVIC 1 from Russia in the 1990s, is currently based at CFTE's flight test facility at Yanliang, Shaanxi Province.

Baghdad-1

Iraqi development with a radar mounted in the cargo hold, used in the Iran–Iraq War.

Baghdad-2

Iraqi development (with French assistance) with fibreglass-reinforced plastic radome over the antenna of the Thomson-CSF Tiger G surveillance radar with a maximum detection range of 350 km (189 nmi, 217.5 mi). One was destroyed on the ground during the 1991 Persian Gulf War; two others were flown to Iran where they remained.[33] At least one went into service with the IRIAF. One aircraft crashed following a midair collision with a HESA Saeqeh fighter, during the annual, Iranian military parade in Teheran.[34] It can be distinguished from the Beriev A-50 by having the Il-76 navigator windows in the nose, which the A-50 does not.

Military and civil operators in 38 countries have operated 850+ Il-76 in large numbers. While Russia is the largest military operator of the Il-76, followed by Ukraine and India, Belarus' TransAVIAexport Airlines is the largest civilian operator.

The People's Liberation Army Air Force operates 17 Il-76 aircraft, including three kJ-2000 AEW&C versions and some Il-78 tankers, with a further 30 due for delivery. However, the deal for new IL-476 is canceled, instead China received ten refurbished IL-76 from Russia and is currently developing its own transport the Xian Y-20.[38][39]

As of April 2018 a total of 80 Il-76 series aircraft have been written off in crashes and other incidents,[51] including the following:

On 23 November 1979, a Soviet Air Force Il-76, registration CCCP-86714, banked left during an approach to Vitebsk Airport. Control of the aircraft was lost and the aircraft crashed, killing the crew of seven; this was the first loss of an Il-76.[52]

On 27 November 1996, a Russian Air Force Ilyushin Il-76MD, registration RA-78804, flew into the hillside of a mountain, minutes after it departed Abakan Airport, and crashed 14 kilometres (8.7 mi) from the airport. All 21 occupants on board lost their lives in the accident.[55][56]

On 19 February 2003, an Ilyushin Il-76 crashed near Kerman, Iran under unspecified reasons (possibly weather-related). The crash killed 275 people, including hundreds of the Iranian Revolutionary Guard.

On 8 May 2003, the rear loading ramp of an Il-76 leased by the Congolese government unexpectedly opened at 10,000 feet after taking off from the capital Kinshasa. Initial reports were that over 120 policemen and their families had been sucked out in 45 minutes,[57] but actual losses were only 14.[58]

On 15 January 2009, two Russian Ministry of Interior Il-76MDs were involved in a ground collision at Makhachkala Airport. One of the aircraft, registration RA-76825, was ready to depart and was positioned at the runway end when the other one, RA-76827, came into land. The wing of the landing aircraft struck the flight deck of RA-76825 and a fire erupted. There were three fatalities in the departing aircraft, out of seven occupants on board. None of the 31 occupants aboard RA-76827 were hurt. RA-76825 was written off as a consequence of the accident.[59][60]

On 9 March 2009 Aerolift Il-76 S9-SAB crashed into Lake Victoria just after takeoff from Entebbe Airport, Uganda, killing all 11 people on board. Two of the engines had caught fire on takeoff. The aircraft was chartered by Dynacorp on behalf of AMISOM. The accident was investigated by Uganda's Ministry of Transport, which concluded that all four engines were time-expired and that Aerolift's claim that maintenance had been performed to extend their service lives and the certification of this work could not be substantiated.[61]

On 1 November 2009, an Il-76 belonging to the Russian Ministry of the Interior, crashed near the city of Mirny within 2 kilometers after taking off. Eleven people on board were confirmed as killed.[64]

On 28 November 2010 Sun Way Flight 4412, Il-76 4L-GNI, crashed in a populated area of Karachi, Pakistan, shortly after taking off from Jinnah International Airport. All eight people on board were killed, along with two people on the ground. The aircraft was reported to have been trying to return to Jinnah after suffering an engine fire.[65]

On 6 July 2011 a Silk Way Il-76, tail number 4K-AZ55, crashed into a mountain in Afghanistan, while on final to Bagram Air Force Base. Eight people on board were initially confirmed as killed, with one unaccounted.[66][67]

On 1 July 2016 an Il-76TD (RA-76840) operated by the Russian Ministry of Emergency Situations (EMERCOM) went missing in the Irkutsk region while fighting a forest fire; the wreckage was found on 3 July 9 km (5.6 mi) east-southeast of Rybnyi Uyan, Kachug Region on the side of a volcano in the area of an active forest fire; the bodies of the ten crew members were also found. Accident remains under investigation.[70]

On 11 April 2018 an Il-76TD (7T-WIV) operated by the Algerian Air Forcecrashed just after takeoff from an airport at Boufarik — less than 30km from the capital Algiers—killing at least 257 soldiers and civilians on board.[71]

1.
Airlift
–
An airlift is the organized delivery of military supplies or military personnel primarily via military transport aircraft. Airlifting consists of two types, strategic and tactical airlifting. Typically, strategic airlifting involves moving material long distances, whereas a tactical airlift focuses on deploying resources, depending on the situation, airlifted supplies can be delivered by a variety of means. When the destination and surrounding airspace is considered secure, the aircraft land at an appropriate airport or airbase to have its cargo unloaded on the ground. However, when the area is too small for this method, as with a base, and/or is too dangerous to land in. Serbian Air Force, made first transport of wounded soldiers from Serbia through Albania to Corfu and that was the first Medevac operation in air history. April 1923 aircraft of the RAFs Iraq Command flew 280 Sikh troops from Kingarban to Kirkuk in the first British air trooping operation, the worlds first long-range combat airlift took place in July 1936. Luftwaffe Ju 52 and Italian Air Force Savoia-Marchetti SM.81 were used by the Spanish Nationalists to transport troops from Spanish Morocco to Spain at the beginning of the Spanish Civil War. Airlifts became practical during World War II as aircraft became large and this joint effort is estimated to have saved more than a million lives in Biafra. Most airplanes departed from the Portuguese colony of Sao Tome and Principe to the landing strip of Uli, the only operational airport in Biafra. Flights were made flying at night all lights off and under near-total radio silence to avoid Nigerian MIG aircraft. All the airplanes, crews and logistics were paid, set up, JCA and their crews and aircraft kept flying into Biafra at the cost of many crews lives. Strategic airlift is the use of transport aircraft to transport materiel, weaponry. Typically, this involves airlifting the required items between two airbases which are not in the same vicinity and this allows commanders to bring items into a combat theater from a point on the other side of the planet, if necessary. Aircraft which perform this role are considered strategic airlifters and this contrasts with tactical airlifters, such as the C-130 Hercules and Transall C-160, which can normally only move supplies within a given theater of operations. This difficulty has prompted investment in lighter armoured fighting vehicles, as well as some research into alternative airlift technologies such as ground effect vehicles. Civilian aircraft are commonly used for transportation. For some civilian airlines, such as Miami Air International and Volga-Dnepr Airlines, tactical airlift is a military term for the airborne transportation of supplies and equipment within a theatre of operations

2.
Ukrainian Air Force
–
The Ukrainian Air Force is a part of the Armed Forces of Ukraine. Ukrainian Air Force headquarters is located in the city of Vinnytsia, when the Soviet Union dissolved in 1991, a large number of aircraft were left on Ukrainian territory. Ever since, the Ukrainian air force has been downsizing and upgrading its forces, in spite of these efforts, the main inventory of the air force consists of Soviet-made aircraft. Currently 36,300 personnel and 144 aircraft are in service in the Ukrainian air force and air defense forces, all ICBMs and strategic bombers have been taken out of service. Since 1991s Ukrainian independence the air force has suffered from chronic underinvestment, the air force currently takes part in the War in Donbass. Following the 5 September 2014 ceasefire Ukraine Air Force has been forbidden from carrying out missions in the areas of Donbass. The major mission of the Air Force is to protect the air space of Ukraine, in peace-time, this is carried out by flying air-space control missions over the entire territory of Ukraine, and by preventing air space intrusion along the aerial borders. Every single day, more than 2,200 service personnel and civilian employees of the Air Force, employing 400 items of weapons, on average, the Ukrainian radar forces detect and track more than 1,000 targets daily. As a result, in 2006 two illegal crossings of the border were prevented and 28 violations of Ukrainian air space were prevented. Due to such increased strengthening of air control, the number of air space violations decreased by 35% compared to the previous year. Previously during the World War I on the Eastern Front, Pavlenko was in charge of air security of the Russian Stavka. Sometimes in 1918 the West Ukrainian Peoples Republic created its own aviation corps with the Ukrainian Galician Army headed by Petro Franko, in 1918 he organized an aviation school of the Ukrainian Galician Army Command Center which was active until 1920. Among the airplanes used by the Ukrainian aviation were Belgium-built SPAD S. VIIs, the Ukrainian Galician Army used Nieuport 17 biplanes. The Ukrainian Air Force was established on March 17,1992, the headquarters of the 24th Air Army of the Soviet Air Force in Vinnytsia served as the basis to create Air Force headquarters. Also present on Ukrainian soil were units of the former Soviet 5th, 14th, in addition, the 161st Maritime Fighter Aviation Regiment, at Limanskoye in Odessa Oblast, came under Ukrainian control. It had formerly been part of the 119th Maritime Fighter Aviation Division of the Black Sea Fleet, the new Air Force inherited the 184th Guards Heavy Bomber Aviation Regiment of Tupolev Tu-160 Blackjack which were based at Pryluky. Discussions with Russia concerning their return bogged down, the main bone of contention was the price. While Russian experts, who examined the aircraft at Pryluky in 1993 and 1996, assessed their technical condition as good, the negotiations led to nowhere and in April 1998, Ukraine decided to commence scrapping the aircraft under the Nunn-Lugar Cooperative Threat Reduction Agreement

3.
Indian Air Force
–
The Indian Air Force is the air arm of the Indian armed forces. It is the fourth largest air force in terms of both personnel and aircraft. Its primary responsibility is to secure Indian airspace and to conduct aerial warfare during a conflict and it was officially established on 8 October 1932 as an auxiliary air force of the British Empire and the prefix Royal was added in 1945 in recognition of its services during World War II. After India became independent from the United Kingdom in 1947, the Royal Indian Air Force served the Dominion of India, since independence, the IAF has been involved in four wars with neighbouring Pakistan and one with the Peoples Republic of China. Other major operations undertaken by the IAF include Operation Vijay, Operation Meghdoot, Operation Cactus, apart from conflicts, the IAF has been an active participant in United Nations peacekeeping missions. The President of India serves as Supreme Commander of the IAF, the Chief of Air Staff, an air chief marshal, is a four-star officer and commands the Air Force. There is never more than one serving ACM at any time in the IAF. The IAF provides close air support to the Indian Army troops in the battlefield and also provides strategic, IAF also provides infantry and artillery transportations or secondary Airlift for the Indian Army. The IAF provided extensive assistance to relief operations during natural calamities such as the Gujarat cyclone in 1998, the IAF also provides assistance to other countries during relief activities such as Operation Rainbow in Sri Lanka. On 1 April 1933, the IAF commissioned its first squadron, No.1 Squadron, with four Westland Wapiti biplanes, the Indian pilots were led by RAF Commanding officer Flight Lieutenant Cecil Bouchier. During World War II, the IAF played a role in blocking the advance of the Japanese army in Burma. It also carried out missions against the Japanese airbases at Mae Hong Son, Chiang Mai. The IAF was mainly involved in Strike, Close Air Support, Aerial reconnaissance, Bomber Escort, RAF Pilots were embedded in IAF units and vice versa to gain combat experience. IAF pilots participated in air operations in Europe as part of the RAF, during the war, the IAF went through a phase of steady expansion. New aircraft, including the US built Vultee Vengeance, Douglas DC-3, in recognition of the services rendered by the IAF, King George VI conferred the prefix Royal in 1945. Thereafter the IAF was referred to as the Royal Indian Air Force, in 1950, when India became a republic, the prefix was dropped and it reverted to being the Indian Air Force. After it became independent from the British Empire in 1947, British India was partitioned into the new states of the Dominion of India, along the lines of the geographical partition, the assets of the air force were divided between the new countries. The RIAF Roundel was changed to an interim Chakra roundel derived from the Ashoka Chakra, around the same time, conflict broke out between them over the control of the princely state of Jammu & Kashmir

4.
Ilyushin Il-78
–
The Ilyushin Il-78 is a Soviet four-engined aerial refuelling tanker based on the Il-76. The Il-76 tanker was conceived as long ago as 1968, but the fuel load for the initial version was only ten tonnes. When the higher performance Il-76 became available the project was restarted in 1982 as the Il-78. In addition to the fuel load of the late model Il-76. In addition, four aircraft can also be refuelled on the ground using conventional refuelling hoses extending from the freight hold, soon after the Il-78 passed acceptance tests in 1984, Ilyushin was instructed to design and produce an upgraded version to be known as Il-78M. The Il-78M is a tanker and cannot be converted back to the transport role easily. Adding a third freight hold tank increased transferable fuel to 105,720 kg and maximum weight to 210,000 kg. UPAZ-1M refuelling pods improved maximum fuel flow to 2,900 l/min, because the Il-78M is not convertible, all cargo handling equipment was removed and cargo doors were deleted, saving approximately 5,000 kg in structural weight. This modification was served to isolate the pod from turbulence generated by the fuselage, some Il-78s were produced with Aeroflot colours and civilian registrations, but production Il-78Ms received military markings, registration and colour scheme. The majority of the twenty Il-78 aircraft of the Ukrainian Air Force have been converted to pure transports, freight hold tanks. All Russian Air Force Il-78s are now part of the special 203rd Orlovski Regiment of aerial tankers, Il-78 The Il-78 was the original production version with two removable fuselage tanks and a maximum transferable load of 85.72 tonnes. Il-78T Alternative designation for Il-78 due to retention of all cargo handling equipment, Il-78M The Il-78M entered service in 1987 as a dedicated tanker equipped with three permanent fuselage tanks, a higher gross weight of 210 tons, and no cargo door or cargo handling equipment. The cargo ramp is retained but non-functional, total fuel capacity is 138 tonnes, of which 105.7 tonnes is transferable. Prototype will be delivered to 2015, Il-78MKI Customized variant of the Il-78ME for the Indian Air Force. These Uzbekistan-built planes are fitted with Israeli fuel transfer systems and can refuel six-eight Sukhoi Su-30MKIs in one mission, Il-78MP Multi-role aerial refuelling tanker/transport aircraft, with removable fuel tanks in cargo hold and UPAZ refuelling pods, for the Pakistan Air Force, and Chinese Air Force. As of March 2009, more than 34 Il-78s were in operation, algeria Algerian Air Force China Chinese Air Force -3 Il-78MP. India Indian Air Force -6 Il-78MKI, the Indian Air Force refers to the aircraft as MARS and has raised a new unit. India is also considering procurement of six more Il-78 after scrapping deal with Airbus, libya Libyan Air Force Pakistan Pakistan Air Force - four Il-78MP aircraft were ordered from Ukrainian surplus aircraft stocks, fitted with removable fuel tanks and UPAZ refuelling pods

5.
Beriev A-50
–
The Beriev A-50 is a Soviet airborne early warning and control aircraft based on the Ilyushin Il-76 transport. The existence of the A-50 was revealed in 1980 by Adolf Tolkachev, developed to replace the Tupolev Tu-126 Moss, the A-50 first flew in 1978. It entered service in 1984, with about 40 produced by 1992, the mission personnel of the 15-man crew derive data from the large Liana surveillance radar with its antenna in an over-fuselage rotodome, which has a diameter of 29 ft 9 in. Detection range is 650 km for air targets and 300 km for ground targets, the A-50 can control up to 10 fighter aircraft for either air-to-air intercept or air-to-ground attack missions. The A-50 is capable of flying for 4 hours at 1000 km from its base at a takeoff weight of 190 tons. The aircraft can be refuelled by Il-78 tankers, the radar Vega-M is designed by MNIIP, Moscow, and produced by NPO Vega. The Vega-M is capable of tracking up to 150 targets simultaneously within 230 kilometers, large targets, like surface ships, can be tracked at a distance of 400 km. After completing State Joint Tests, Beriev has delivered the first upgraded Airborne Early Warning, the aircraft,47 Red/RF-92957 was handed over at Berievs facility in Taganrog on October 31,2011. A second aircraft,33 Red is getting upgraded and is due for delivery in 2012 and these are the only two production upgrades ordered to date, but Beriev anticipates further orders. Development work on the A-50U began some years ago and state tests started on September 10,2008, the main element of the modernisation involves replacing the outdated analogue equipment with a new, digital avionics suite supplied by Vega Radio Engineering Corporation JSC. Notable improvements include faster data processing, enhanced signal tracking, crew rest, toilet and galley facilities are also included in the upgrade. These upgrades form the basis of the concept for Beriev A-100 AEW&C, configuration will be similar to the A-50U, but with a new Vega Premier active electronically scanned array radar. In late December 2015, the A-50 started operations over Syria, flying from Russia, a-50M – Modernized Russian Version fitted with mid-air refueling capability. A-50U – updated Russian variant Izdeliye-676 – One-off stop-gap telemetry and tracking aircraft, izdeliye-776 – One-off stop-gap telemetry and tracking aircraft. Izdeliye-976 – – Il-76 based Range Control and Missile tracking platform, initially built to support Raduga Kh-55 cruise missile tests. Has fixed radar cover filled with equipment and glassed navigator cockpit. Izdeliye-1076 – One-off special mission aircraft with unknown duties,50 Squadron IAF, Agra Air Force Station –3 operational, RFP for 2 more sent to IAI for the EL/W-2090 AEW&C radar system to be mounted on the A-50

6.
Turbofan
–
The turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. Thus, whereas all the air taken in by a turbojet passes through the turbine, a turbofan thus can be thought of as a turbojet being used to drive a ducted fan, with both of those contributing to the thrust. The ratio of the mass-flow of air bypassing the engine compared to the mass-flow of air passing through the core is referred to as the bypass ratio. Most commercial aviation jet engines in use today are of the high-bypass type, afterburners are not used on high-bypass turbofan engines but may be used on either low-bypass turbofan or turbojet engines. Other noise sources are the fan, compressor and turbine, Jet noise is reduced with chevrons, sawtooth patterns on the exhaust nozzles, on the Rolls-Royce Trent 1000 and General Electric GEnx engines used on the Boeing 787. Turbofans are thus the most efficient engines in the range of speeds from about 500 to 1,000 km/h, turbofans retain an efficiency edge over pure jets at low supersonic speeds up to roughly Mach 1.6. Modern turbofans have either a large single-stage fan or a fan with several stages. An early configuration combined a low-pressure turbine and fan in a single rear-mounted unit, early turbojet engines were not very fuel-efficient as their overall pressure ratio and turbine inlet temperature were severely limited by the technology available at the time. In 1939-1941 Soviet designer Arkhip Lyulka elaborated the design for the worlds first turbofan engine, although several prototypes were built and ready for testing, Lyulka was in 1941 forced to abandon his research and evacuate to the Urals following the Nazi invasion of the Soviet Union. So the first turbofan to run was apparently the German Daimler-Benz DB670 with a first run date of 27 May 1943, turbomachinery testing, using an electric motor, had started on 1 April 1943. The engine was abandoned later while the war went on and problems could not be solved, the British wartime Metrovick F.2 axial flow jet was given a fan, as the Metrovick F.3 in 1943, to create the first British turbofan. The original low-bypass turbofan engines were designed to improve efficiency by reducing the exhaust velocity to a value closer to that of the aircraft. The Rolls-Royce Conway, the worlds first production turbofan, had a ratio of 0.3. Civilian turbofan engines of the 1960s, such as the Pratt & Whitney JT8D and the Rolls-Royce Spey had bypass ratios closer to 1, the first General Electric turbofan was the aft-fan CJ805-23 based on the CJ805-3 turbojet. It was followed by the aft-fan General Electric CF700 engine with a 2.0 bypass ratio and this was derived from the General Electric J85/CJ610 turbojet to power the larger Rockwell Sabreliner 75/80 model aircraft, as well as the Dassault Falcon 20 with about a 50% increase in thrust. The CF700 was the first small turbofan in the world to be certified by the Federal Aviation Administration, there were at one time over 400 CF700 aircraft in operation around the world, with an experience base of over 10 million service hours. The CF700 turbofan engine was used to train Moon-bound astronauts in Project Apollo as the powerplant for the Lunar Landing Research Vehicle. A high-specific-thrust/low-bypass-ratio turbofan normally has a fan, developing a relatively high pressure ratio and, thus

7.
Soviet Union
–
The Soviet Union, officially the Union of Soviet Socialist Republics was a socialist state in Eurasia that existed from 1922 to 1991. It was nominally a union of national republics, but its government. The Soviet Union had its roots in the October Revolution of 1917 and this established the Russian Socialist Federative Soviet Republic and started the Russian Civil War between the revolutionary Reds and the counter-revolutionary Whites. In 1922, the communists were victorious, forming the Soviet Union with the unification of the Russian, Transcaucasian, Ukrainian, following Lenins death in 1924, a collective leadership and a brief power struggle, Joseph Stalin came to power in the mid-1920s. Stalin suppressed all opposition to his rule, committed the state ideology to Marxism–Leninism. As a result, the country underwent a period of rapid industrialization and collectivization which laid the foundation for its victory in World War II and postwar dominance of Eastern Europe. Shortly before World War II, Stalin signed the Molotov–Ribbentrop Pact agreeing to non-aggression with Nazi Germany, in June 1941, the Germans invaded the Soviet Union, opening the largest and bloodiest theater of war in history. Soviet war casualties accounted for the highest proportion of the conflict in the effort of acquiring the upper hand over Axis forces at battles such as Stalingrad. Soviet forces eventually captured Berlin in 1945, the territory overtaken by the Red Army became satellite states of the Eastern Bloc. The Cold War emerged by 1947 as the Soviet bloc confronted the Western states that united in the North Atlantic Treaty Organization in 1949. Following Stalins death in 1953, a period of political and economic liberalization, known as de-Stalinization and Khrushchevs Thaw, the country developed rapidly, as millions of peasants were moved into industrialized cities. The USSR took a lead in the Space Race with Sputnik 1, the first ever satellite, and Vostok 1. In the 1970s, there was a brief détente of relations with the United States, the war drained economic resources and was matched by an escalation of American military aid to Mujahideen fighters. In the mid-1980s, the last Soviet leader, Mikhail Gorbachev, sought to reform and liberalize the economy through his policies of glasnost. The goal was to preserve the Communist Party while reversing the economic stagnation, the Cold War ended during his tenure, and in 1989 Soviet satellite countries in Eastern Europe overthrew their respective communist regimes. This led to the rise of strong nationalist and separatist movements inside the USSR as well, in August 1991, a coup détat was attempted by Communist Party hardliners. It failed, with Russian President Boris Yeltsin playing a role in facing down the coup. On 25 December 1991, Gorbachev resigned and the twelve constituent republics emerged from the dissolution of the Soviet Union as independent post-Soviet states

8.
Aerial refueling
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The procedure allows the receiving aircraft to remain airborne longer, extending its range or loiter time on station. A series of air refuelings can give range limited only by crew fatigue, alternatively, a shorter take-off roll can be achieved because take-off can be at a lighter weight before refueling once airborne. Aerial refueling has also considered as a means to reduce fuel consumption on long-distance flights greater than 3,000 nautical miles. Potential fuel savings in the range of 35-40% have been estimated for long haul flights, usually, the aircraft providing the fuel is specially designed for the task, although refueling pods can be fitted to existing aircraft designs if the probe-and-drogue system is to be used. There is no known regular civilian in-flight refueling activity, for instance, in the Gulf War and the Iraqi invasion of Kuwait and the Iraq War, all coalition air sorties were air-refueled except for a few short-range ground attack sorties in the Kuwait area. The first mid-air refueling, based on the development of Alexander P. de Seversky, as the 1920s progressed, greater numbers of aviation enthusiasts vied to set new aerial long-distance records, using inflight air refueling. One such enthusiast, who would revolutionize aerial refueling was Sir Alan Cobham, member of the Royal Flying Corps in World War I, and a pioneer of long-distance aviation. During the 1920s, he made long-distance flights to places as far afield as Africa and Australia and this craft was eventually modified by Airspeed to Cobhams specification, for a non-stop flight from London to India, using in-flight refueling to extend the planes flight duration. Meanwhile, in 1929, a group of U. S. Army Air Corps fliers, led by then Major Carl Spaatz, set an endurance record of over 150 hours with the Question Mark over Los Angeles. Aerial refueling remained a dangerous process until 1935 when brothers Fred and Al Key demonstrated a spill-free refueling nozzle. They exceeded the Hunters record by nearly 100 hours in a Curtiss Robin monoplane, the US was mainly concerned about transatlantic flights for faster postal service between Europe and America. In 1931 W. Irving Glover, the assistant postmaster, wrote an extensive article for Popular Mechanics concerning the challenges. In his article he even mentioned the use of Aerial refueling after take off as a possible solution, by 1931 they had demonstrated refueling between two Vickers Virginias, with fuel flow controlled by an automatic valve on the hose which would cut off if contact was lost. Royal Air Force officer Richard Atcherley had observed the dangerous aerial-refueling techniques in use at barnstorming events in the US and determined to create a workable system. In 1934, Cobham sold off the airline Cobham Air Routes Ltd to Olley Air Service, atcherlys system was bought up by Cobhams company, and with some refinement and continuous improvement through the late 30s, it became the first practical refueling system. Sir Alan Cobhams Grappled-line looped-hose air-to-air refueling system borrowed from techniques patented by David Nicolson and John Lord, and was publicly demonstrated for the first time in 1935. In the system the aircraft, at one time an Airspeed Courier, trailed a steel cable which was then grappled by a line shot from the tanker. The line was drawn back into the tanker where the receivers cable was connected to the refueling hose

9.
Mile
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The mile is an English unit of length of linear measure equal to 5,280 feet, or 1,760 yards, and standardised as exactly 1,609.344 metres by international agreement in 1959. The Romans divided their mile into 5,000 feet but the importance of furlongs in pre-modern England meant that the statute mile was made equivalent to 8 furlongs or 5,280 feet in 1593. This form of the mile then spread to the British-colonized nations who continue to employ the mile, the US Geological Survey now employs the metre for official purposes but legacy data from its 1927 geodetic datum has meant that a separate US survey mile continues to see some use. Derived units such as miles per hour and miles per gallon, however, continue to be abbreviated as mph, mpg. The modern English word mile derives from Middle English myl and Old English mīl, the present international mile is usually what is understood by the unqualified term mile. When this distance needs to be distinguished from the nautical mile, in British English, the statute mile may refer to the present international miles or to any other form of English mile since the 1593 Act of Parliament which set it as a distance of 1,760 yards. Under American law, however, the statute mile refers to the US survey mile, the mile has been variously abbreviated—with and without a trailing period—as m, M, ml, and mi. The American National Institute of Standards and Technology now uses and recommends mi in order to avoid confusion with the SI metre and millilitre. Derived units such as miles per hour and miles per gallon, however, continue to be abbreviated in the United States, United Kingdom, the BBC style holds that There is no acceptable abbreviation for ‘miles’ and so it should be spelt out when used in describing areas. The Roman mile consisted of a thousand paces as measured by every other step—as in the distance of the left foot hitting the ground 1,000 times. The ancient Romans, marching their armies through uncharted territory, would push a carved stick in the ground after each 1000 paces. Well-fed and harshly driven Roman legionaries in good weather thus created longer miles, the distance was indirectly standardised by Agrippas establishment of a standard Roman foot in 29 BC, and the definition of a pace as 5 feet. An Imperial Roman mile thus denoted 5,000 Roman feet, surveyors and specialized equipment such as the decempeda and dioptra then spread its use. In modern times, Agrippas Imperial Roman mile was empirically estimated to have been about 1,481 metres in length, in Hellenic areas of the Empire, the Roman mile was used beside the native Greek units as equivalent to 8 stadia of 600 Greek feet. The mílion continued to be used as a Byzantine unit and was used as the name of the zero mile marker for the Byzantine Empire. The Roman mile also spread throughout Europe, with its local variations giving rise to the different units below, also arising from the Roman mile is the milestone. All roads radiated out from the Roman Forum throughout the Empire –50,000 miles of stone-paved roads, at every mile was placed a shaped stone, on which was carved a Roman numeral, indicating the number of miles from the center of Rome – the Forum. Hence, one knew how far one was from Rome

Rolls-Royce Conway low bypass turbofan from a Boeing 707. The bypass air exits from the fins whilst the exhaust from the core exits from the central nozzle. This fluted jetpipe design is a noise-reducing method devised by Frederick Greatorex at Rolls-Royce

An Aeroflot PS-84 (a Douglas DC-3, modified by fitment of Soviet engines) at Moscow City Airport in 1940. The Lisunov Li-2, a license-built version of the DC-3, would become the backbone of the fleet after the Great Patriotic War.

After its introduction in 1954, the Ilyushin Il-14 operated on Aeroflot's All-Union services.